Nemophora diplophragma (Meyrick, 1938) Liao & Hirowatari & Yagi & Wang & Wang & Huang, 2023

Liao, Cheng-Qing, Hirowatari, Toshiya, Yagi, Sadahisa, Wang, Min, Wang, Xing & Huang, Guo-Hua, 2023, The fauna of the family Adelidae (Insecta, Lepidoptera, Adeloidea) from China, Zootaxa 5348 (1), pp. 1-152 : 30

3.6 Nemophora diplophragma species group

Diagnosis. This species group can be distinguished by the following characters: the male eyes are relatively large, close to each other dorsally, with eye size index 1.6–2.8; the forewing has a near triangular basal spot whose outer margin is more or less connected with anterior and posterior margins; the transverse central fascia is placed near half of the forewing, yellow to orange-yellow; the forewing ground color is black with blue-purple luster, usually scattered with many yellow scales apically; and the apex of aedeagus with a distinct point spine.

Remarks. This species group consists of three species, namely, N. diplophragma ( Meyrick, 1938) , N. basalistriata sp. nov., and N. digitata sp. nov., all of which are distributed in China. Among them, N. diplophragma has not been reported since it was first described based on a single specimen from Yunnan, China ( Meyrick 1938). The other two species are new ones described in this study. This species group is very similar to the Nemophora aurifera group which shares the above characters 3 and 4. However, the large eyes in male and yellow basal spots are distinct diagnosis characters of this species group.

Key to species of the diplophragma group based on external morphology and male genitalia

1 Basal spot and transverse central fasciae of forewing both distinctly large and wide.................... N. diplophragma

- Basal spot very small, triangular or linear; transverse central fasciae of forewing distinctly narrow..................... 2

2 Forewing obviously narrow, forewing length about 3.2 × width; valva with acute apex; median process of transtilla very short; suspensorium small, anterior part not beyond posterior margin of vinculum in ventral view......... N. duplicifascia sp. nov.

- Forewing obviously broad, forewing length about 2.8 × width; valva with rounded or quadrate apex; median process of transtilla very long; anterior part of suspensorium significantly beyond posterior margin of vinculum in ventral view.............. 3

3 Triangular yellow spot of forewing base relatively large, exceeding to costal and posterior margins; transverse central fascia narrower on costal margin than posterior margin............................................... N. digitata sp. nov.

- Triangular yellow spot of forewing base relatively small, not exceeding to costal margin; transverse central fascia narrower on posterior margin than costal margin..................................................... N. basalistriata sp. nov.